Machine for knitting tubular envelopes



July 14, 1931. F. MEIWALD 1,814,324

MACHINE FOR KNITTING TUBULAR ENVELOPES Filed Nov. 22, 1929 2 Sheets-Shee 1 [1 012 %abm [4 Patented July 14, 1931 r UNITED STATES PATENT OFFICE FRANZ MEIWALD, OF VIENNA, AUSTRIA MACHINE FOR KNITTING TUBULAR ENVELOPES Application filed November 22, 1929, Serial No. 408,961, and in Austria December 18, 1928.

I have filed an application for this patent velope opened out flat, both views illustratin Austria on Dec. 18, 1928; in Germany on ing the manner in which the loops are biased Dec. 27, 1928; in Czechoslovakia on January in accordance with the invention. Fig. 3 3, 1929, of which the following is a specifishows by way of example a form of construc- 5 cation. tion of the. portions of the knitting machine This invention relates to machines for which effect the formation of the loops. Fig. making flexible cord-like knitted tubular en- 4 is a partial longitudinal section of the knitvelopes, for use on sheathing electric conting machine. Fig. 5 is a section on the line ducting wires with a covering of knitted fab- 5-5 of Fig. 4. Fig. 6 shows the drive of the 10 rie, and has for its object to provide a mamachine. (50 chine for knitting an envelope in such a man- \Vhereas the successive loops in a line lie, 1101' as to increase the durability of the knitin the ease of the ordinary knitted envelope, ted envelope. The knitted envelopes heretoparallel to the longitudinal axis of the fore employed for covering a flexible electric tubular envelope, the lines of the loops in 15 conductor have not been of an altogether sucthe envelope made on my improved ma- 65 cessful and practical character, for the reason ehiue (Figs. 1 and 2) are twisted spirally. that, in consequence of the indispensable im- When the cord is sharply bent, the tensile pregnation of the envelope with a waterstrain to which the loops on the convex sideprooling agent, the threads of the fabric are of the bend are submitted is transferred to the rendered insuilieicntly elastic and yielding, laterally adjacent loops, which are less 7 so that when the conductor is bent the outer strained. In the case. of the impregnated threads of the fabric of the casing, i. c. those protective casing for instance of electric conon the convex surface of the bend, become ductors this point is of importance, since the torn and broken apart. flexibility of the threads after having been 25 The present invention avoids this objection hardened by subsequent impregnation is nat- 7-:

by providing that the threads of the stitching urally slight from the start. of the tubular envelope do not lie parallel to The type of knitting machine taken for the the longitudinal axis of the envelope but example shown in the drawings of a type obliquely thereto, so that the rows follow a of construction of a knitting machine for steep spiral curve. This arrangement of the producing the envelope according to the inso loops prevents their becoming torn when the vention is that in which the cam box and reel cord is sharply bent, since the tensile strain plate are rotating. produced along the length of the envelope on Referring particularly to Figs. 3 to 6, incluits convex side at the bend is transferred to sive, the needle cylinder 1 fitted with the neeother portions of the outside surface of the dles 2 is screwed into a hollow shaft 3 and B5 tubular envelope. The twisting of the rows held in its position of vertical adjustment by of loops in regard to each other is carried out a nut 4. A knitting cam 5 of the usual conby means of a knitting machine embodying struction is inserted in a cam box 6, which is r the present invention. connected for rotation to a block 7 attached In the invention as here shown, the twist is to the reel plate 8. The cam box 6 together produced by providing besides the usual with the knitting cam 5 and the needle cylindrive for the cam cylinder andbobbin carder 1 are interchangeable. Cam boxes and rier, an actuating mechanism for imparting., needle cylinders of different diameters can a rotation to the needle bed which is rather be inserted in the machine. The reel plate 43 slow with relation to the rotation of the cam 8 is attached to a drum 9 (Figs. 4 and 6), cylinder and which causes the twist in all the the hub of which carries a bevel wheel 10 mesh rows. and is freely rotatable on a bearing-block 12 Fig. 1 of the drawings shows an envelope mounted on the bed-plate 11. A ball bearing of improved construction made by a machine is interposed between the hub of the drum 9 m embodying my invention, and Fig. 2 the enand the bearing-block 12. The shaft 3 of the PM is brought up over the a cone pulley 17 on a shaft 18 mounted in bearings on. the bed-plate 11. The shaft 18 drives through the agency of the toothed wheels 19, 20 a shaft 21, whichcarries a worm 22, which engages a worm-wheel attached to the lower end of the shaft 3.

A guide 27 is attached by means of spokes 26 to the upper ring 25 ofthe reel plate 8 carrying the reels 24 and ends in a cone immediately above the needle cylinder 1, and serves for the feeding in of the core, which guide-wheel 28. The guide-wl1eel28 is secured to a shaft 29, which is mounted in a bracket projecting upwards" from the bed-plate 11, and is set in rotation by the main drive. For this purpose the shaft 15 is fitted with a bevel wheel 31, which engages a bevel wheel 33 attached to a vertical shaft 32. The shaft 32 is mounted at its upper end in a bearing 34 in a bracket (not shown in the drawings) of the bed-plate 11 and is fitted with a worm 35, by means of which through the agency of a worm-wheel and gearing (Fig. 6) the guide-wheel 28 is riven at a speed corresponding to that of the production of the finished envelope. The ratio of the speed-of the reel plate 8 to that of the needle cylinder 1 is regulated with the help of the cone pulleys 16, 17 If the needle cylinder, which is stationary in ordina knitting machines, is driven in the same direction of rotation as the cam box 6 but at a comparatively slow speed, the ratio of the two speeds bein preferably 1:10, the loops are formed in t e manner shown in Figs. 1 and 2, the lines of the consecutive loops fol lowing a steep spiral round the tubular envelope.

The same effect can of course be achieved y means of a machine with rapidly rotating needle cylinder by the slow rotation of the cam box and reel plate. The same effect can also be achieved irrespective of the construction of the knitting machine by im arting an additional rotating movement to t e core, which then, in consequence of friction, produces the twisting of the envelope; this method, however is seldom attempted, since it implies the r tation of the supply drum and the entire guiding machinism of the core.

For the carrying out of the invention a single knitting machineis sufficient, since the latter is capable of meeting all needs within wide limits by the changin of the cylinder and of the cam box. The degree of the obliqueness of the loops can be varied by adjustment of the speed of the needle cylinder and of the cam box and reel plate, When the core is of larger diameter the loops will naturally be formed lon er and vice versa, this result being achieved y lowerin or raising the position of the needle cylin er.

I claim 1. Machine for circum-knitting. tubular cords for electric conductors, including a needle bed, a cam cylinder, and a spool carrier, drive means for the cam cylinder, and an additional drive means which is adapted to impart to the needle bed a rotary movement which is slow relative tothe rotary speed of the cam cylinder and which causes the tubular cord to be twistedlydeformed.

2. In a machine for knitting a tubular cord for electrical conductors, a knitting mechanism including a rotating cam cylinder and a rotatable spool .carrier, a rotatable needle bed, and means for rotating the needle bed at a slow speed relating to that of the cam cylinder.

In testimony whereof I aflix my signature.

FRANZ MEIWALD. 

